Re: [PATCH v2] mm: use mem_map_offset instead of mem_map_next

[Cheng Li <lic121@chinatelecom.cn>]

On Tue, Sep 06, 2022 at 05:10:48PM -0700, Andrew Morton wrote:
> On Tue, 6 Sep 2022 10:07:03 -0700 Mike Kravetz <mike.kravetz@oracle.com> wrote:
> 
> > On 09/05/22 06:09, Cheng Li wrote:
> > > To handle discontiguity case, mem_map_next() has a parameter named
> > > `offset`. As a function caller, one would be confused why "get
> > > next entry" needs a parameter named "offset". The other drawback of
> > > mem_map_next() is that the callers must take care of the map between
> > > parameter "iter" and "offset", otherwise we may get an hole or
> > > duplication during iteration. So we use mem_map_offset instead of
> > > mem_map_next.
> > > 
> > > Signed-off-by: Cheng Li <lic121@chinatelecom.cn>
> > > Fixes: 69d177c2fc70 ("hugetlbfs: handle pages higher order than MAX_ORDER")
> > 
> > The Fixes tag implies there is a user visible bug.  I do not believe this is
> > the case here.  Is there a user visible bug?
> 
> A Fixes: with a cc:stable would indicate a user-visible bug.  But IMO a
> bare Fixes: is simply a when-to-stop guide to backporters - a
> convenience.  And, I suppose, it has some documentation benefit.
> 
> And if people are really that interested, they can read the dang
> changelog ;)
> 

Thank you for the reviews and the "Fixes" tag tips.

So seems we are agrenment on replacing mem_map_offset() with nth_page().
I may need to send the version 3 :)

I learnt the "Fixes" tag usage from this kenrel contribution guide.[1]

[1]
https://www.kernel.org/doc/html/v4.17/process/submitting-patches.html#using-reported-by-tested-by-reviewed-by-suggested-by-and-fixes